• We are sorry, but NCBI web applications do not support your browser and may not function properly. More information
Logo of plantsigLink to Publisher's site
Plant Signal Behav. Oct 1, 2012; 7(10): 1346–1348.
PMCID: PMC3493423

Acoustic and magnetic communication in plants

Is it possible?

Abstract

Over the last two decades, important insights into our understanding of plant ecology and the communicative nature of plants have not only confirmed the existence of a wide range of communication means used by plants, but most excitingly have indicated that more modalities remain to be discovered. In fact, we have recently found that seeds and seedlings of the chili plant, Capsicum annuum, are able to sense neighbors and identify relatives using alternative mechanisms beyond previously studied channels of plant communication. In this addendum, we offer a hypothetical mechanistic explanation as to how plants may do this by quantum-assisted magnetic and/or acoustic sensing and signaling. If proven correct, this hypothesis prompts for a re-interpretation of our current understanding of plasticity in germination and growth of plants and more generally, calls for developing a new perspective of these biological phenomena.

Keywords: signaling, cues, mechanoreception, magnetoreception, quantum coherence, acoustic resonance

The idea that plants communicate has long been a controversially debated topic, because the flow of information between plants was often thought to involve cues rather than actual signals. This distinction is important because signals are traits that evolved for a specific role in communication (see definition by Scott-Phillips1), while cues are only incidental features present in the environment that have not been shaped by natural selection to carry a specific meaning for intended receivers and which most researchers agree should not be considered communicative in nature.2,3 Excitingly, important insights into our understanding of plant ecology, and specifically chemical signaling, have confirmed that plants are capable of both cue- and signal-mediated interactions,4 processing information about their neighbors both above-5 and below-ground,6-8 and sharing information about the resources available in their surroundings. We now know that plants can signal to each other about approaching insect attacks and even allow for pre-emptive defensive responses4,9-11 using an extensive ‘vocabulary’ of chemical molecules, such as herbivore-induced volatile organic compounds (VOCs). Similarly, plants have been shown to exchange information to recognize and even prevent costly competitive interactions with relatives,12,13 hence facilitating kin selection processes such as cooperation and altruism. And recently, we have learnt that plants are even able to exchange information to solve a problem as a group (i.e., root swarm intelligence14,15), just like many animal groups, from honeybees to humans. Thus over the past two decades, our perspective on plant communication has been revolutionized through an exponential increase in research effort in this area of investigation (Fig. 1). Such progress has been accompanied by a better appreciation of the wide diversity in communication means available to plants, and opened up the possibility that more modalities remain to be uncovered.

figure psb-7-1346-g1
Figure 1. Current status of plant communication research. (A) Number of papers published in each year on the topic 'Plant Communication' starting from 1970 till today (larger diagram) and (B) citation rates for the same topic over the same time ...

In a recent study, we intentionally blocked above- and below-ground contact, chemical and light-mediated signals and revealed the existence of uncharted communication channels used by seeds and seedling to sense neighbors and identify relatives. Specifically, we showed that young chilli plants are able to sense their neighbors from as early as the seed stage. Furthermore as seeds grow into seedlings, they are able to discriminate among neighboring species and modify their growth patterns accordingly, without necessarily relying on known determinants, such as volatile chemicals, direct physical contact or changes in infrared light wavelengths. So what are the modalities involved for plants to perform these feats? In our recent paper, we suggested two possible explainations for the observed results, namely magnetic and/or acoustic fields, which may allow plants to recognize their neighbors. Clearly the underlying condition for any of these sensory modalities to function as a channel for the transfer of information is that plants are both able to detect such fields and, equally importantly, produce and emit them (or alter fields produced elsewhere). From a detection point of view, we have ample evidence of both magneto- and mechanoreception in plants, and the bewildering variety of plant responses to both magnetic fields (i.e., strong continuous fields as well as alternating magnetic fields)16,17 and vibrational/sound waves.18,19 It is not surprising that plants are endowed with mechanisms adapted to sensing and transducing such fields and vibrations; indeed like all living organisms, plants have evolved in and adapted to an environment rich in naturally occurring and fluctuating geophysical waveforms of both magnetic (e.g., extremely low frequency magnetic fields known as Schumann resonances20) and acoustic origin (e.g., the resonant acoustic free oscillations known as the Earth’s “hum”21), and they are likely to have learnt to exploit the opportunities for sensory monitoring of such environment to thrive in it.20-22 Yet, preliminary evidence of plants producing and emitting them has emerged only recently (i.e., plant magnetism23; plant bioacoustics24) and how exactly plants do so is still elusive.

The mechanisms generating both magnetic fields and acoustic waves in plants may be driven by similar biochemical processes within the cell, where nanomechanical oscillations of various components in the cytoskeleton can generate a spectrum of vibrations spanning from low kHz up to GHz25,26 and even up to THz.27 Specifically, Corsini et al.23 suggested that electrical currents and time-varying electric fields, which in turn are generated by ionic flows and time varying ionic distributions, might produce plant magnetic fields. Similarly, acoustic waves may be generated as a result of mechanical vibrations of charged cell membranes and walls through alteration of their potentials28 and/or through the activity of mechanochemical enzymes such as myosins, which use chemical energy derived from the hydrolysis of ATP in actin filaments to generate mechanical vibrations within cells.18 Interestingly, the radiated power of numerous cells working in a collective mode (i.e., coherent excitation26) has been theoretically predicted to be sufficient for observable effects, leading to acoustic flows in the order of 150–200 kHz.28 Indeed, the existence of coherent, non-localized phenomena has been previously reported in plants (e.g., quantum coherence in marine algae photosynthesis29) and such an approach may prove very fruitful in understanding how plants emit magnetic fields and acoustic waves. Ultimately, if such magnetic fields and mechanical vibrations can extend over large distances within the organism and also outside the organism, then there is a real possibility that plants may indeed use these means to communicate with other plants or organisms.

Footnotes

References

1. Scott-Phillips TC. Defining biological communication. J Evol Biol. 2008;21:387–95. doi: 10.1111/j.1420-9101.2007.01497.x. [PubMed] [Cross Ref]
2. Bradbury JW, Vehrencamp SL. Principles of animal communication. Sinauer, Sunderland, 1998.
3. Maynard Smith J, Harper D. Animal signals. Oxford, UK: University Press, 2006.
4. Falik O, Mordoch Y, Quansah L, Fait A, Novoplansky A. Rumor has it...: relay communication of stress cues in plants. PLoS One. 2011;6:e23625. doi: 10.1371/journal.pone.0023625. [PMC free article] [PubMed] [Cross Ref]
5. Smith H. Physiological and ecological function within the phytochrome family. Annu Rev Plant Physiol Plant Mol Biol. 1995;46:289–315. doi: 10.1146/annurev.pp.46.060195.001445. [Cross Ref]
6. Gersani M, Brown JS, O’Brien EE, Maina GM, Abramsky Z. Tragedy of the commons as a result of root competition. J Ecol. 2001;89:660–9. doi: 10.1046/j.0022-0477.2001.00609.x. [Cross Ref]
7. Gruntman M, Novoplansky A. Physiologically mediated self/non-self discrimination in roots. Proc Natl Acad Sci U S A. 2004;101:3863–7. doi: 10.1073/pnas.0306604101. [PMC free article] [PubMed] [Cross Ref]
8. Murphy GP, Dudley SA. Above- and below-ground competition cues elicit independent responses. J Ecol. 2007;95:261–72. doi: 10.1111/j.1365-2745.2007.01217.x. [Cross Ref]
9. Paré PW, Tumlinson JH. Plant volatiles as a defense against insect herbivores. Plant Physiol. 1999;121:325–32. doi: 10.1104/pp.121.2.325. [PMC free article] [PubMed] [Cross Ref]
10. Karban R, Baldwin IT, Baxter KJ, Laue G, Felton GW. Communication between plants: induced resistance in wild tobacco plants following clipping of neighboring sagebrush. Oecologia. 2000;125:66–71. doi: 10.1007/PL00008892. [Cross Ref]
11. Heil M, Ton J. Long-distance signalling in plant defence. Trends Plant Sci. 2008;13:264–72. doi: 10.1016/j.tplants.2008.03.005. [PubMed] [Cross Ref]
12. Dudley SA, File AL. Kin recognition in an annual plant. Biol Lett. 2007;3:435–8. doi: 10.1098/rsbl.2007.0232. [PMC free article] [PubMed] [Cross Ref]
13. Murphy GP, Dudley SA. Kin recognition: Competition and cooperation in Impatiens (Balsaminaceae) Am J Bot. 2009;96:1990–6. doi: 10.3732/ajb.0900006. [PubMed] [Cross Ref]
14. Baluška F, Lev-Yadun S, Mancuso S. Swarm intelligence in plant roots. Trends Ecol Evol. 2010;25:682–3. doi: 10.1016/j.tree.2010.09.003. [PubMed] [Cross Ref]
15. Ciszak M, Comparini D, Mazzolai B, Baluska F, Arecchi FT, Vicsek T, et al. Swarming behavior in plant roots. PLoS One. 2012;7:e29759. doi: 10.1371/journal.pone.0029759. [PMC free article] [PubMed] [Cross Ref]
16. Galland P, Pazur A. Magnetoreception in plants. J Plant Res. 2005;118:371–89. doi: 10.1007/s10265-005-0246-y. [PubMed] [Cross Ref]
17. Belyavskaya NA. Biological effects due to weak magnetic field on plants. Adv Space Res. 2004;34:1566–74. doi: 10.1016/j.asr.2004.01.021. [PubMed] [Cross Ref]
18. Telewski FW. A unified hypothesis of mechanoperception in plants. Am J Bot. 2006;93:1466–76. doi: 10.3732/ajb.93.10.1466. [PubMed] [Cross Ref]
19. Gagliano. Green symphonies: a call for studies on acoustic communication in plants. In review. [PMC free article] [PubMed]
20. Zhadin MN. Review of russian literature on biological action of DC and low-frequency AC magnetic fields. Bioelectromagnetics. 2001;22:27–45. doi: 10.1002/1521-186X(200101)22:1<27::AID-BEM4>3.0.CO;2-2. [PubMed] [Cross Ref]
21. Nishida K, Kobayashi N, Fukao Y. Resonant oscillations between the solid earth and the atmosphere. Science. 2000;287:2244–6. doi: 10.1126/science.287.5461.2244. [PubMed] [Cross Ref]
22. Arnason BT, Hart LA, O’Connell-Rodwell CE. The properties of geophysical fields and their effects on elephants and other animals. J Comp Psychol. 2002;116:123–32. doi: 10.1037/0735-7036.116.2.123. [PubMed] [Cross Ref]
23. Corsini E, Acosta V, Baddour N, Higbie JM, Lester B, Licht P, et al. Search for plant biomagnetism with a sensitive atomic magnetometer. J Appl Phys. 2011;109:074701. doi: 10.1063/1.3560920. [Cross Ref]
24. Gagliano M, Mancuso S, Robert D. Towards understanding plant bioacoustics. Trends Plant Sci. 2012;17:323–5. doi: 10.1016/j.tplants.2012.03.002. [PubMed] [Cross Ref]
25. Pokorný J, Jelínek F, Trkal V, Lamprecht I, Hölzel R. Vibrations in microtubules. J Biol Phys. 1997;23:171–9. doi: 10.1023/A:1005092601078. [PMC free article] [PubMed] [Cross Ref]
26. Pokorný J. Conditions for coherent vibrations in the cytoskeleton. Bioelectrochem Bioenerg. 1999;48:267–71. doi: 10.1016/S0302-4598(99)00016-1. [PubMed] [Cross Ref]
27. Frohlich H. The biological effects of microwaves and related questions. Adv Electron Electron Phys. 1980;53:85–152. doi: 10.1016/S0065-2539(08)60259-0. [Cross Ref]
28. Perelman ME, Rubinstein GM. Ultrasound vibrations of plant cells membranes: water lift in trees, electrical phenomena. http://arxiv.org/abs/physics/0611133; 2006.
29. Collini E, Wong CY, Wilk KE, Curmi PMG, Brumer P, Scholes GD. Coherently wired light-harvesting in photosynthetic marine algae at ambient temperature. Nature. 2010;463:644–7. doi: 10.1038/nature08811. [PubMed] [Cross Ref]

Articles from Plant Signaling & Behavior are provided here courtesy of Landes Bioscience
PubReader format: click here to try

Formats:

Related citations in PubMed

See reviews...See all...

Cited by other articles in PMC

See all...

Links

Recent Activity

Your browsing activity is empty.

Activity recording is turned off.

Turn recording back on

See more...